I'm still at the early chapters though.
That's definitely it. Soon you'll get upgrades that make special enemies trivial, like a shield upgrade that clears all shields when thrown. After that you can finish the entire game without switching weapons once.
Poopfeast420@discuss.tchncs.de 2 days ago
I played on default Nightmare and then some custom turbo mode (150% game speed with lower damage taken and dealt, and a bit more).
As the OP said, after a few levels you can get upgrades that destroys shielded enemies quickly and for some reason the game starts spawning mostly superheated ones anyway, so you can just instantly blow those groups up.